In some statewide positions, people come and go fast, taking several keys to success when they leave.

In just a four-year term, it’s not uncommon for a governor to watch high-level officials walk out the door -- sometimes several times for the same job.

Though there are no studies indicating which positions have the highest turnover, at least three have tended to come up in conversations with government officials over the last years: Medicaid directors, secretaries of health and human services, and chief information officers. Each tend to change leadership roughly every year and a half.

“Even in a year when we’ve only had a few new governors, we expect about 10 [new CIOs],” says Doug Robinson, executive director of the National Association of State Chief Information Officers.

That’s not a big shock. Many CIOs come from the private sector and are drawn by the prospect of serving the public. But when they get to the job, “they’re often surprised about the environment and how difficult it can be to move the ball forward,” says Robinson. “They’re not used to the bureaucratese.”

Such high turnover is hazardous to a state’s smooth functioning. When someone leaves a job, several keys to success are lost.

For one, “you lose institutional knowledge,” says Bill Leighty, former chief of staff for the Commonwealth of Virginia who now works in consulting.

However qualified the replacement for that job may be, progress will slow until the new leader understands all the moving parts of the work. This is especially true for Medicaid directors, who have been dealing with dramatic changes as a result of the landmark Affordable Care Act.

“Having turnover makes it challenging to keep your foot on the pedal,” says Matt Salo, executive director of the National Association of Medicaid Directors.

Knowledge (or lack thereof) isn’t the only thing that stunts progress. Frequent leadership transitions also lead to a loss of relationships, which is what makes many high-ranking state officials most effective. A sense of trust builds over time that helps people work together better. But when an official walks out the door, the relationships leave with them.

As painful as these premature exits may be, they sometimes have benefits.

“It can be a healthy disruption when it lets people take a step back and see if they’re meeting the mission of the organization,” says Tracey Wareing Evans, executive director of the American Public Human Services Association. “A new leadership comes in with a new set of questions. So it’s not all negative.”

But why do many officials depart more frequently than the governors for whom they work?

On occasion, it’s due to a well-publicized negative event. In child welfare agencies, for example, “when there’s an unnecessary death of a child in the system, many times a qualified person needs to leave,” says Wareing.

This can be true whether or not the official had any real responsibility for the deaths. Doug Racine, now a consultant, fell victim to the tendency to purge leaders after tragedy strikes. After two children died under his watch as the secretary of human services in Vermont, he was fired months later. But there was no public statement connecting him to the deaths.

“The reviews of those child fatalities all pointed to the lack of adequate staffing,” he explains. “not only in child protection but judiciary and so on. It was a systems issue.”

Far more frequently, though, state officials leave for other reasons. That’s because men and women with the kind of expertise for these jobs can easily find more lucrative work in the private sector. Then there’s the stress associated with many high-level state positions, which can lead to premature burnout.

“Many [Medicaid directors] say they could easily spend 100 percent of their time putting out fires, but they also have to spend a fair amount of time thinking about the future,” says Salo. “They universally say that it was the hardest job they’ve ever loved.”